"These plants are most efficacious in the inflaming of the brain, and are therefore much used in Confusing and Befuddlement Draughts, where the wizard is desirous of producing hot-headedness and recklessness…"

Harry Potter read about Befuddlement Draughts while trying to complete homework one night in his fifth year.
His mind was so consumed by worried thoughts that he repeatedly read the same passage of text and then fell asleep with the book still in his hands.[1]